The Epidermis is a thin cellular membrane layer; containing keratin. The epidermis is the outermost totally cellular layer of the skin. It is composed of squamous epithelium . The epithelium is the covering of both the internal and external surfaces of the body.
1. Thin, cellular membrane layer containing keratin; outermost layer of skin. 2. Dense, fibrous, connective tissue layer; contains collagen. 3. Thick, fat-containing tissue.
Skin that has four layers of cells is referred to as "thin skin." From deep to superficial, these layers are the stratum basale, stratum spinosum, stratum granulosum, and stratum corneum. Most of the skin can be classified as thin skin. "Thick skin" is found only on the palms of the hands and the soles of the feet.
keratin cells which produce keratin, the fibrous protein that makes the epidermis a tough protective layer stratum basale the deepest cell layer of the epidermis; lies closest to the dermis and is connected to it along a wavy borderline that resembles corrugated cardboard; contains the most adequately nourished of the epidermal cells because nutrients diffusing from the dermis …
the epidermisWhat are the layers of the epidermis? Deepest layer of the epidermis. New skin cells develop in this layer, and it also contains the keratinocyte (cur-at-in-o-site) stem cells, which produce the protein keratin. Keratin helps form hair, nails and your skin's outer layer, which protect you from the harsh environment.Oct 19, 2021
stratum corneumThe stratum corneum is the most superficial layer of the epidermis and is the layer exposed to the outside environment (see (Figure)). The increased keratinization (also called cornification) of the cells in this layer gives it its name. There are usually 15 to 30 layers of cells in the stratum corneum.
Stratum Granulosum This is the layer where part of keratin production occurs. Keratin is a protein that is the main component of skin.
Structures presentStructuresThin skinThick skinHair folliclesContains hair folliclesNo hair folliclesStratum lucidumNo stratum lucidum layerStratum lucidum layer in the epidermisStratum corneumThin stratum corneum layerThick stratum corneum layerStratum granulosumSingle layer of cells4–5 cells thick6 more rows•May 12, 2021
keratin, fibrous structural protein of hair, nails, horn, hoofs, wool, feathers, and of the epithelial cells in the outermost layers of the skin. Keratin serves important structural and protective functions, particularly in the epithelium.
The stratum granulosum (or granular layer) is a thin layer of cells in the epidermis lying above the stratum spinosum and below the stratum corneum (stratum lucidum on the soles and palms). Keratinocytes migrating from the underlying stratum spinosum become known as granular cells in this layer.
Skin is thickest on the palms and soles of the feet (1.5 mm thick), while the thinnest skin is found on the eyelids and in the postauricular region (0.05 mm thick).Nov 29, 2017
The squamous cell layer is the thickest layer of the epidermis, and is involved in the transfer of certain substances in and out of the body. The squamous cell layer also contains cells called Langerhans cells.
What is the major histological difference between thick and thin skin? Where on the body is each type of skin found? thick skin is found on the palms of the hand and soles of the feet. Thick skin is 0.5 mm thick, while Thin skin is about 0.1mm thick.
Thin skin means that the epidermis is not as thick as it should be. The hypodermis may also have less fat, which results in this layer being thinner, too. By itself, thinner skin should not cause any medical problems. However, a person may find that their skin gets damaged or bruises more easily.
Definition: Thin skin is the type that is found covering most parts of the body excluding certain parts of the hands and feet. It does also vary in thickness with the thinnest layers being found in areas such as the eyelids, for instance.
Thin skin is the skin covering most of the body parts except the soles of feet, palms, and the surface lining of fingers and toes. It has a thinner epidermis and contains sebaceous glands, sweat glands, hair follicles, and arrector pili muscles.
Figure 5.1.1 – Layers of Skin: The skin is composed of two main layers: the epidermis, made of closely packed epithelial cells, and the dermis, made of dense, irregular connective tissue that houses blood vessels, hair follicles, sweat glands, and other structures. Beneath the dermis lies the hypodermis, which is composed mainly ...
Most of the skin can be classified as thin skin. “Thick skin” is found only on the palms of the hands and the soles of the feet. It has a fifth layer, called the stratum lucidum, located between the stratum corneum and the stratum granulosum ( Figure 5.1.2 ).
The epidermis is composed of keratinized, stratified squamous epithelium. It is made of four or five layers of epithelial cells, depending on its location in the body. It does not have any blood vessels within it (i.e., it is avascular). Skin that has four layers of cells is referred to as “thin skin.” From deep to superficial, these layers are the stratum basale, stratum spinosum, stratum granulosum, and stratum corneum. Most of the skin can be classified as thin skin. “Thick skin” is found only on the palms of the hands and the soles of the feet. It has a fifth layer, called the stratum lucidum, located between the stratum corneum and the stratum granulosum ( Figure 5.1.2 ).
As the name suggests, the stratum spinosum is spiny in appearance due to the protruding cell processes that join the cells via a structure called a desmosome. The desmosomes interlock with each other and strengthen the bond between the cells. It is interesting to note that the “spiny” nature of this layer is an artifact of the staining process. Unstained epidermis samples do not exhibit this characteristic appearance. The stratum spinosum is composed of eight to 10 layers of keratinocytes, formed as a result of cell division in the stratum basale ( Figure 5.1.5 ). Interspersed among the keratinocytes of this layer is a type of dendritic cell called the Langerhans cell, which functions as a macrophage by engulfing bacteria, foreign particles, and damaged cells that occur in this layer.
The stratum basale (also called the stratum germinativum) is the deepest epidermal layer and attaches the epidermis to the basal lamina, below which lie the layers of the dermis. The cells in the stratum basale bond to the dermis via intertwining collagen fibers, referred to as the basement membrane.
There are usually 15 to 30 layers of cells in the stratum corneum. This dry, dead layer helps prevent the penetration of microbes and the dehydration of underlying tissues, and provides a mechanical protection against abrasion for the more delicate, underlying layers.
Two other cell types are found dispersed among the basal cells in the stratum basale.
The cells become flatter, their cell membranes thicken, and they generate large amounts of the proteins keratin and keratohyalin. The nuclei and other cell organelles disintegrate as the cells die, leaving behind the keratin, kerato hyalin, and cell membranes that form the stratum lucidum and the stratum corneum.
The pigment melanin , produced by melanocytes, is primarily responsible for skin color, carotene (yellow/orange), and hemoglobin (red/pink) are also skin pigments. Melanin comes in different shades of brown and black.
Scars are made of collagen and do not have the cellular structure of normal skin. The tissue is fibrous and does not allow for the regeneration of accessory structures, such as hair follicles, and sweat or sebaceous glands. Upgrade to remove ads. Only $2.99/month.
Nails are composed of densely packed dead keratinocytes. They protect the fingers and toes from mechanical stress. The nail body is formed on the nail bed, which is at the nail root. Nail folds, folds of skin that overlap the nail on its side, secure the nail to the body.
Explanation: The skin consists of two layers: a stratified squamous epithelium called the epidermis and a deeper connective tissue layer called the dermis. Below the dermis is another connective tissue layer, the hypodermis, which is not part of the skin.
The stratum corneum consists of up to 30 layers of dead, scaly, keratinized cells that form a durable surface layer. Label the cell types found in the skin. The epidermis is composed of five types of cells. Stem cells are undifferentiated cells that divide and give rise to the keratinocytes.
The stratum granulosum consists of three to five layers of flat keratinocytes—more in thick skin than in thin skin. The stratum lucidum is a thin zone superficial to the stratum granulosum, seen only in thick skin.
A hair is divisible into three zones along its length: (1) the bulb, a swelling at the base where the hair originates in the dermis or hypodermis; (2) the root, which is the remainder of the hair within the follicle; and (3) the shaft, which is the portion above the skin surface.
People of different skin colors have essentially the same number of melanocytes, but in dark skin, the melanocytes produce greater quantities of melanin. Variations in ancestral exposure to UV radiation are the primary reason for the geographic and ethnic variation in skin color today.
Explanation: Apocrine sweat glands have a large lumen and a duct that conveys their aromatic secretion into a hair follicle. Merocrine sweat glands have a relatively narrow lumen and a duct that opens by way of a pore on the skin surface. Consider sebaceous and ceruminous glands.
-Ancestral exposure to UV radiation results in active melanocytes in descendants. Explanation: The most significant factor in skin color is melanin.